We have tested hard disk drives with a capacity of 1 terabyte and three quarters of a terabyte (750GB), and now it’s time to move one step lower, to 640GB devices. This capacity may look odd because the manufacturers usually try to arrive at some round and nice-looking number. The explanation is simple: every 640GB hard disk drive is based on two latest-generation platters with a recording density of 320GB per platter. That’s why 1-terabyte drives use a three-platter design. But it should be noted that 1-terabyte drives have 333GB platters. The manufacturers must have reduced the capacity of each platter to 320GB in order to avoid the sinister number of 666 gigabytes. 640 gigabytes, on its part, is a logical continuation of the capacity growth from 160 through 320 to 640 gigabytes.

Dual-platter HDDs have always had an ambiguous standing. They are not remembered as “the world’s first to achieve the capacity of so many gigabytes” but still enjoy well-deserved popularity. It is dual-platter drives that used to have the lowest data storage cost per gigabyte. They have only been outdone recently after the considerable price cut on 1-terabyte models. You can also expect very good performance from them: each of the five HDDs included into this review is based on full-size 320GB platters whereas there can be drives with lower recoding density among 500GB and 750GB models. Well, it is going to be interesting to compare them!

Testing Participants

Samsung SpinPoint F1 DT, 640GB: HD642JJ

The SpinPoint F1 series provoked a kind of sensation on the HDD market. It is within this series that the world’s first 333GB-platter drives came out (those were 1TB rather than 640GB models). Thanks to it, Samsung successfully enlarged its share of the HDD market and left the group of the lagging brands (Samsung’s HDDs had been inferior to their opponents in maximum capacity). Recently the company’s product range has been complemented with enterprise and economical HDD series, and the desktop series has acquired a small addition to its name. It is now called SpinPoint F1 DT.

Seagate Barracuda 7200.11, 640GB: ST3640323AS

Seagate modernized its Barracuda 7200.11 series at a certain moment, adding 320GB-platter drives into it (the series had been originally based on 250GB platters). This made things more complicated for users looking for highest-performance HDDs because Barracuda 7200.11 drives of the same capacity but with different platters were selling simultaneously. The problem affected the models with capacities of 500, 750 and 1000GB.

Seagate didn’t stop at that, though. Later on, the company introduced a model with an even higher recording density, 375GB per platter, into the Barracuda 7200.11 series. Why? Just to be ahead of its competitors in releasing the world’s first 1.5-terabyte drive (ST31500341AS). The combination of four-platter design and then-densest 375GB platters ensured a tactical win for Seagate.

Unfortunately, this is not going to be the most memorable fact about the series. In mid-January we learned that there was a serious error in the firmware (all firmware versions save for the latest SD2*, CC** and LC**) of all HDDs of the series as well as of the similar ES.2 and Seagate-Maxtor DiamondMax 22 series. Because of that error a fully functional drive would not be identified at all or identified with a capacity of 0 gigabyte at startup. The drive’s data were not destroyed, but you had to go to a service center to read them. After mass media and Seagate forum users had made a racket, the company acknowledged the problem officially and posted firmware updates at its site (by the way, this is only a second case in Seagate’s history when firmware is made officially available for download). So, if you’ve got a drive belonging to this series, we recommend you to visit the acknowledgement link, download the software that identifies your HDD firmware and, if necessary, update the latter. Of course, the problem may pass you by (our sample of the HDD has the problematic firmware, but works normally as yet), but why risk your data?